Busch has more than 71,000 supporters registered to his Facebook page.
Until recently, Charles Cadwallader, a former Ministry of Agriculture and Forestry manager of animal welfare investigations and SPCA national chief inspector, was among the faithful.
But Cadwallader has washed his hands of Busch. In an open letter to Busch supporters he said he'd repeatedly asked about funds from a now-closed UK charity called the Big Cat Rescue Trust but had come up against a "wall of silence".
"If these questions are ignored then people might justifiably be concerned that something untoward has happened to those funds."
Cadwallader worked voluntarily for "Team Busch" for five months. He was concerned first for the welfare of the animals and then for people who could ill-afford to make donations.
But Busch's Tutukaka-based spokesperson Jill Albrow dismissed Cadwallader's fears.
"I always say to people 'Don't give anything that you can't afford' but I'm not concerned that there's anything untoward going on."
Meanwhile, Busch has debts. Whangarei lawyer Wayne Peters is waiting for a court date over about $80,000 in outstanding legal fees. Auckland law firm Foy and Halse has an outstanding judgment for $16,400 and Cadwallader is waiting on a refund of $2700 for an airfare he'd paid for Busch.